The human nose is essentially a pyramid that is divided into three compartments, namely, the bony vault, the upper cartilaginous vault, and the lower cartilaginous vault. The aforesaid vaults have a common supporting partition, the bony and cartilaginous septum.
The bony vault forms the principal structural base for the nose and is made up of upward projections of the frontal process of the maxilla from which a pair of nasal bones extend to form an arch at the union thereof. The posterior border of the bony vault is continuous with the maxilla. If the nose is thought of as being cantilevered, the bony vault forms a stable base, with its arch an extension of the skull. Stated in another manner, the bony vault with its cantilevered upper cartilaginous vault fuses with the dorsal edge of the septum to form a structural "I beam" extending from the radix of the skull to the lower cartilaginous vault.
The upper cartilaginous vault is made up of paired, triangular cartilages that extend from the bony vault as a cantilever and are attached along the dorsal border of the septum by a dense fibrous union. The cartilages are attached to the undersurface of the lateral walls of the bony vault by a membrane. The dorsal segment or upper edge of the upper cartilaginous vault is the bridge that connects the two upper lateral cartilages to give them stability.
The lower cartilaginous vault forms the base of the nose and is made up of tissues caudal to the free edge of the upper lateral cartilages. Although the lower vault is relatively independent of the vaults it shares with them the dorsal edge of the septum and the connective tissue attachments to the upper lateral cartilages.
Upon the occurrence of an accident the dorsum may be fractured or due to rhinoplasty the dorsum may be resected, separating the dorsal edge of the bony cartilaginous vaults from the walls thereof. At this point the cartilaginous vaults must rely on the remaining attachment to the nasal bones for their support. Thus, in order for proper healing to occur, the nasal pyramid must be fully and properly supported.